OPERATING SEGMENT INFORMATION (Tables)

12 Months Ended

Dec. 31, 2023

Segment Reporting, Asset Reconciling Item [Line Items]

Schedule of Segment Reporting Information, by Segment

Operating segment information is as follows (in millions):

	Year Ended December 31, 2023
	Mainline		Regional		Horizon		Consolidating & Other(a)		Air Group Adjusted(b)			Special Items(c)		Consolidated
Operating Revenue
Passenger revenue	$	8,097	$	1,429	$	—	$	—	$	9,526		$	—	$	9,526
CPA revenue	—		—		374		(374)		—			—		—
Mileage Plan other revenue	599		49		—		—		648			—		648
Cargo and other revenue	244		—		—		8		252			—		252
Total Operating Revenue	8,940		1,478		374		(366)		10,426			—		10,426
Operating Expenses
Operating expenses, excluding fuel	5,841		1,121		344		(358)		6,948			443		7,391
Fuel expense	2,264		379		—		—		2,643			(2)		2,641
Total Operating Expenses	8,105		1,500		344		(358)		9,591			441		10,032
Non-operating Income (Expense)	(15)		—		(41)		3		(53)			(18)		(71)
Income (Loss) Before Income Tax	$	820	$	(22)	$	(11)	$	(5)	$	782		$	(459)	$	323
Pretax Margin									7.5		%			3.1		%

	Year Ended December 31, 2022
	Mainline		Regional		Horizon		Consolidating & Other(a)		Air Group Adjusted(b)			Special Items(c)		Consolidated
Operating Revenue
Passenger revenue	$	7,454	$	1,354	$	—	$	—	$	8,808		$	—	$	8,808
CPA revenue	—		—		359		(359)		—			—		—
Mileage Plan other revenue	538		52		—		—		590			—		590
Cargo and other revenue	244		—		—		4		248			—		248
Total Operating Revenue	8,236		1,406		359		(355)		9,646			—		9,646
Operating Expenses
Operating expenses, excluding fuel	5,216		1,085		383		(356)		6,328			580		6,908
Fuel expense	2,195		397		—		—		2,592			76		2,668
Total Operating Expenses	7,411		1,482		383		(356)		8,920			656		9,576
Non-operating Income (Expense)	30		—		(22)		1		9			—		9
Income (Loss) Before Income Tax	$	855	$	(76)	$	(46)	$	2	$	735		$	(656)	$	79
Pretax Margin									7.6		%			0.8		%

	Year Ended December 31, 2021
	Mainline		Regional		Horizon		Consolidating & Other(a)		Air Group Adjusted(b)			Special Items(c)		Consolidated
Operating Revenue
Passenger revenue	$	4,411	$	1,088	$	—	$	—	$	5,499		$	—	$	5,499
CPA revenue	—		—		406		(406)		—			—		—
Mileage Plan other revenue	402		59		—		—		461			—		461
Cargo and other revenue	212		—		—		4		216			—		216
Total Operating Revenue	5,025		1,147		406		(402)		6,176			—		6,176
Operating Expenses
Operating expenses, excluding fuel	4,101		1,096		373		(433)		5,137			(925)		4,212
Fuel expense	1,065		261		—		—		1,326			(47)		1,279
Total Operating Expenses	5,166		1,357		373		(433)		6,463			(972)		5,491
Non-operating Income (Expense)	(38)		—		(21)		3		(56)			—		(56)
Income (Loss) Before Income Tax	$	(179)	$	(210)	$	12	$	34	$	(343)		$	972	$	629
Pretax Margin									(5.6)		%			10.2		%

(a) Includes consolidating entries, Air Group parent company, McGee Air Services, and other immaterial business units.

(b) The Air Group Adjusted column represents the financial information that is reviewed by management to assess performance of operations and determine capital allocations and excludes certain charges.

(c) Includes special items and mark-to-market fuel-hedge accounting adjustments.

	2023		2022		2021
Depreciation and amortization:
Mainline	$	403	$	351	$	323
Horizon	48		64		71
Consolidated	$	451	$	415	$	394
Capital expenditures:
Mainline	$	1,473	$	1,544	$	236
Horizon(a)	200		127		56
Consolidated	$	1,673	$	1,671	$	292
Total assets at end of period:
Mainline	$	19,937	$	19,733
Horizon	1,352		1,157
Consolidating & Other	(6,676)		(6,704)
Consolidated	$	14,613	$	14,186